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Reverse Crunches

The reverse crunch flips the classic crunch: instead of curling the torso toward the hips, you curl the hips off the floor toward the ribcage with the knees drawn in. It biases the lower portion of the abdominal wall and spares the neck entirely, making it a favourite for trainees who find head-up crunching uncomfortable. Coached by Maddy (NASM-CPT) — these are the exact form cues he gives on every client's first week.

Muscles worked

Abs · rectus abdominis Obliques

Sets & reps by goal

GoalSets × RepsRest
Strength4 sets x 4-6 slow reps with a pause at the top90 sec - 2 min
Muscle3 sets x 9-12 reps60-90 sec
Endurance2-3 sets x 18-27 reps30-45 sec

Rep ranges per Helms 2014 · Schoenfeld 2016.

Level — Beginner

Beginner — easy to attempt, but the slow un-curl that makes it worthwhile takes practice to tolerate.

Proper form — 5 cues

  1. Lie on your back with knees bent to 90 degrees and shins parallel to the floor.
  2. Press your arms into the mat beside you like outriggers.
  3. Curl the hips up and back so the knees travel toward your chest.
  4. Peel the lower back off the mat one segment at a time — this is the actual exercise.
  5. Lower the hips with a slow, controlled un-curl until the tailbone settles back down.

Breathing: Exhale fully as the hips curl up — the empty-lungs position deepens the ab contraction — and inhale as you lower.

The 3 mistakes Maddy corrects most

Swinging the knees to throw the hips up.. Momentum from the legs rocks the pelvis over without the abs curling the spine, so the reps look right and train nothing. Fix: Pause the knees dead still before each rep and initiate by tilting the pelvis — think 'curl', never 'kick'.
Pushing hard through the arms to lever the hips up.. Arm drive substitutes triceps and lats for abdominal work, and the habit deepens as sets get harder. Fix: Turn the palms up to disarm the push, or lightly touch the temples with your fingertips on lighter sets.
Letting the hips crash down after the curl.. The lowering phase is half the stimulus, and the crash extends the lower back suddenly under load. Fix: Un-curl on a three-second count, feeling each bit of the lower back re-establish contact with the mat.

Common questions

Do reverse crunches target lower abs specifically?

The rectus abdominis is one sheet of muscle, but movements that curl the pelvis toward the ribs — like this one — produce more activity in its lower region than head-up crunches do. So the bias is real even though full isolation is not. Practically: if the area below your navel never seems to work in ab training, reverse crunches are the sensible first addition.

Are reverse crunches better than regular crunches?

Better for some people, not universally. They win if crunches bother your neck, if you want the lower-abdominal bias, or if you tend to yank your head during sit-up-style work. Regular crunches win for simplicity and for loading the upper region directly. Strong programs often alternate them across the week rather than crowning one.

Why do I feel reverse crunches in my hip flexors?

Because the knees are being lifted by the hip flexors instead of the pelvis being curled by the abs — the most common fault. Fix the intent: keep the knee angle frozen at 90 degrees and think about tipping your belt buckle toward your chin. If the front of the hips still dominates, shorten the range to just the pelvic tilt until the abs learn to lead.

Related exercises

Easier: Crunches

Alternate Leg Raises (Modified)Abs · Hip flexors Butterfly CrunchesAbs Cable Seated in and OutAbs · Hip flexors Chair CrunchesAbs Cross Mountain ClimbersAbs · Hip flexors

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